Ecotoxicological Effects of Pb on Brassice rapa
Pb污染对白菜的生态毒理效应研究

Water culture methods have been used to study Pb enrichment capability and tolerance of Brassice rapa seeds and seedlings. 6 concentrations of Pb were set: 0.2mg·L-1, 0.4mg·L-1, 0.8mg·L-1, 1.6mg·L-1, 3.2mg·L-1 and control. After Brassice rapa seeds cultured in these solution for 7 days, the rate of seed germination, stem growth inhibition rate, root tolerance index, chlorophyll and carotenoid content and the amount of lead concentration were measured. The ability of enrichment and tolerance of Brassice rapa seedlings to Pb studied using the indoor culture technique. The results show that Brassice rapa seedlings had high ability of enrichment to Pb. Roots were main organs of enrichment of Pb. The maximum capacity of the root concentration is 75.46mg·L-1. Pb inhibited Brassice rapa seed germination and seedling growth. With 0.2mg·L-1, Pb promoted the growth of Brassice rapa stems. High concentrations of Pb inhibited the growth of Brassice rapa stem. Pb inhibited the chlorophyll synthesis and Carotenoids and the normal growth of Brassice rapa seedlings. Brassice rapa has a certain tolerance to Pb.